1. Technical Field
The present invention relates generally to premises based wireless networks wherein wireless terminals roam between network segments and utilize address resolution techniques for data packet routing purposes; and, more particularly, it relates to techniques for enhancing the mobility of such wireless terminals within the wireless networks while minimizing wireless traffic for address resolution.
2. Related Art
Communication systems often include interconnected wired and wireless networks that together support communication within an enterprise. These communication systems typically include one or more wired networks that connect network elements such as workstations, servers and access points. Communication cells established by wireless access points (APs) provide links between network elements connected to the wired backbone and mobile terminals. Such communications often pass through both the wireless and wired networks.
Wired networks typically operate according to one or more communication protocols, or protocol stacks that were specifically designed with strategies to maintain and manage wired networks. Similarly, wireless networks have evolved with protocols and associated maintenance strategies to support mobile network nodes and other unique characteristics associated with wireless network. Thus, it is often difficult to merge wired and wireless networks together without degrading performance on either the wired or wireless network.
For example, in conventional installations, APs are used to bridge between the wired and wireless networks. However, higher level protocols operating in the wired networks often create problems for the wireless networks, especially in those wireless networks where terminals frequently roam. Specifically, when terminals that communicate with a first AP on one IP (internet protocol) segment of a wired LAN (local area network) roam to communicate with a second AP attached to a second IP segment of the wired LAN, ongoing communication may be lost due to the a need to reregister the roaming device on the second IP segment and unregister that device from the first IP segment. Thus, IP nodes cannot transparently roam to another IP subnet. Further, because the APs in different IP segments often reside adjacent one another, the roaming terminals frequently move back and forth between the cells, creating significant problems in the network.
In order to overcome the shortcomings described above and additional shortcomings, a wireless network according to the present invention includes a multi-segment wired network and a plurality of wireless access points connected to the wired network. The wired network operates according to a wired network protocol which may be the Internet Protocol. Wireless terminals communicate with the wireless access points according to the wired network protocol, inconsistent with the wireless network protocol. Each of the wireless terminals has a wired network address corresponding to one of the wireless access points. As the wireless terminals roam throughout the premises, protocol tunnels route communications between wireless terminals via the wired network, thereby preserving communications while roaming by allowing the wireless terminals to retain their wired network addresses during the ongoing communications. Such protocol tunnels are transparent to the wired network.
Additional functionality is provided through the use of data link tunnels that connect access points within a wireless network. The data link tunnels allow passage of data under the wired network protocol to wireless terminals operating under the wired network without extraneous overhead in a communications protocol.